Display units of the thin type, such as LCD (liquid crystal display), ELD (electroluminescent display) and PDP (plasma display panel), are used in recent years for showing image data or information on television sets and personal computers. More particularly, small LCDs are used in electronic devices having high functionality, such as cellular phones or portable telephones and digital still cameras, for displaying image information, device setting information and information as to the status or state of the device.
With electronic devices equipped with such a display unit, the display unit is generally housed in the cabinet of the electronic device and has a display panel which is visible through an opening of the cabinet. Many of display units provided in small devices show setting information (e.g., characters showing the operation mode) or state information (e.g., a graphic representation indicating the remaining capacity of battery) in a region in close proximity to an edge of the opening. In assembling the electronic device, therefore, the display unit must be fixed to the cabinet, as positioned in the opening with high accuracy. Otherwise, the information will become partly hidden by the cabinet after the electronic device has been completed. In view of the assembling work efficiency, it is also desired that the electronic device have a mechanism permitting the display unit to be positioned and fixed in place readily.
The prior art relating to the positioning and fixing of display units will be described with reference to the camera disclosed in JP-A No. 11-149121 (1999) as an example of electronic device. FIGS. 11a and 11b are sectional views showing an LCD 70 incorporated into the camera and members around the display. By a flexible printed circuit board (hereinafter referred to as “FPC”) 71, the LCD 70 is connected to a main body (not shown) having various block units and a pressure plate 85 attached thereto. An outer cover 80 attached to the main body has an opening 81 through which the LCD 70 is exposed. An EL sheet 87 is held between the LCD 70 and the pressure plate 85.
FIG. 11a shows a first example of the conventional apparatus. In assembling the camera, the LCD 70 is first dropped into a recess 86 formed in the pressure plate 85 and is thereby attached to the pressure plate 85. The outer cover 80 is then attached to the main body. At this time, the LCD 70 is positioned in place relative to the opening 81 by positioning pieces 82, 82 provided on the rear side of the cover 80. The LCD 70 is further pressed and fixed by pressure pieces 83, 83.
FIG. 11b shows a second conventional example. The outer cover 80 is provided on the rear side thereof with a second positioning piece 84 for forming a U-shaped groove, in addition to a positioning piece 82 and pressure pieces 83, 83. In assembling the camera, the LCD 70 is first fitted into a space between the positioning piece 82 and the second positioning piece 84, whereby the LCD 70 is positioned in place relative to the opening 82 of the outer cover 80. When the outer cover 80 is attached to the main body, the LCD 70 is fixed in place.
However, the display positioning mechanism of the conventional electronic device described and the procedure for assembling the mechanism have the problems to be described below.
First, the conventional mechanism fails to position the LCD 70 relative to the opening 81 with high accuracy. To fit in the LCD 70 in the conventional example, the distance between reference faces of the positioning pieces 82, 82 (FIG. 11a) or the distance between reference faces of the positioning piece 82 and the second positioning piece 84 (FIG. 11b) must be slightly greater than the vertical width of the LCD 70. This permits the LCD 70 to backlash, impairing accuracy in positioning the LCD 70. Even if high accuracy is ensured in positioning the LCD 70 relative to the pressure plate 85 and fixing the display thereto, and when the outer cover 80 is thereafter attached to the main body, it is likely that the position of the outer cover 80 relative to the main body will involve an error. The LCD 70 then becomes shifted relative to the opening 81 by an amount corresponding to the error.
Further with the first conventional example, the LCD 70 is connected in an unstable state to the main body by the FPC 71. Accordingly, even if dropped into the recess 86 formed in the pressure plate 85, the LCD 70 will be moved out of the recess 86 easily by a slight impact. Since the worker needs to handle the main body so that the LCD 70 will not be removed from the recess 86, the posture of the main body is limited during the procedure for attaching the outer cover 80, thereby resulting in a poor work efficiency.
In the case where the LCD 70 is attached to the outer cover 80 first as in the second conventional example, FPC 71 needs to have a length greater than the length thereof required for connection to the main body. The worker performs the work while holding the outer cover 80 with one hand and holding the LCD 70 with the other hand. If the FPC 71 has an increased length, the range in which the FPC 71 is movable enlarges, making the LCD 70 easy to attach. However, the camera then needs to have an enlarged space in its interior for accommodating the FPC 71. In addition, there arises a need to add to the assembling work the step of making the bent form of the FPC 71 suitable for accommodation.